Abstract:
Mechanically flexible aluminum nitride–silicone rubber composites (SAN) were prepared by hot pressing technique for different filling fractions. The effects
of filler content on the dielectric, thermal and mechanical properties as well as on moisture absorption were investigated.
The relative permittivity and dielectric loss of the composite were found to vary linearly with filler content.The variation in relative permittivity of SAN composites
with temperature was also investigated at a frequency of 1 MHz. Theoretical modelling of relative permittivity of the composites was performed and the results were correlated
with the experimental data. Among the theoretical models effective medium theory is in good agreement with experimental
values of relative permittivity. The coefficient of thermal expansion and specific heat capacity of the composite
were found to decrease with filler content and thermal conductivity, thermal diffusivity and the moisture
absorption increased with filler loading. The SAN composite is found to be a good candidate for a thermally conductive flexible microwave substrate application
